us-east-1 is part of the suite of chaos engineering tools AWS offers.

The whole point is to use multiple Availability Zones across Regions, to protect your uptime from failures in single AZs or entire Regions. Amazon.com does that.

And yet, even companies like pager duty, who have “one job” and hire many competent engineers, still struggle with this:

https://www.pagerduty.com/blog/outage-post-mortem-june-14/

Note that pager duty now weathers Amazon outages beautifully, but the point is that amazon doesn’t have 100% uptime and that properly designing distributed systems is very hard.